Read the links below about various ways to pay for items in the iTunes and App Stores.
- Add a payment method to your account. See this article about payment methods that you can use with your Apple ID --> Payment methods that you can use with your Apple ID - Apple Support then see this article about how to add a payment method to your Apple ID --> Add a payment method to your Apple ID - Apple Support
- Add money to your Apple ID balance - "Use a payment method, such as a credit or debit card, to add funds to your Apple ID balance." This takes the previous payment method one step farther by optionally using it to irreversibly add funds to an Apple ID account balance instead of having the card charged each time.
Click here --> Add money to your Apple Account balance - Apple Support
- This article outlines how to redeem an Apple Gift Card or App Store & iTunes gift card --> How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support